Neoxanthin is an allenic xanthophyll and a precursor of the plant hormone abscisic acid, which is formed as the last product of carotenoid synthesis in green plants. Synonyms: (3S,3'S,5R,5'R,6R,6'S,9'-cis)-6,7-Didehydro-5',6'-epoxy-5',6'-dihydro-beta,beta-carotene-3,3',5(6H)-triol;…